sparkr-interpreter/src/main/resources/kernelR/sparkr_runner_utils.R

#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License
#

#
# Reduces a collection of character vectors to a single character vector of
# length 1
#
# obj: The object representing the character vector to flatten
# shouldTrim: If true, will trim each individual element
# sepCharacter: Used as the separator between combined strings
#
flatten <- function(obj, shouldTrim = TRUE, sepCharacter = "\n") {
  Reduce(function(x, y) {
    flattenedX <- if (length(x) > 1) flatten(x) else x
    flattenedY <- if (length(y) > 1) flatten(y) else y

    finalX <- if (shouldTrim) trimws(flattenedX) else flattenedX
    finalY <- if (shouldTrim) trimws(flattenedY) else flattenedY

    paste(finalX, finalY, sep = sepCharacter)
  }, obj)
}